Abstract: The thirst for new sources of energy is unquenchable, but we seldom realize that we are wasting a part of the electrical energy everyday due to the lagging power factor in the inductive loads we use. Hence, there is an urgent need to avoid this wastage of energy. Before getting into the details of Power Factor Correction, let us just brush our knowledge about the term ?power factor?. In simple words, power factor basically states how far the energy provided has been utilized. The maximum value of power factor is unity. So the closer the value of power factor to unity, better is the utility of energy or lesser is the wastage. In electrical terms, power factor is basically defined as the ratio of active power to reactive power or it is the phase difference between voltage and current. Active power performs useful work while reactive power does no useful work but is used for developing the magnetic field required by the device. Most of the devices we use have power factor less than unity. Hence, there is a requirement to bring this power factor close to unity. Here we are presenting a prototype for automatic power factor correction using the 8-bit AVR microcontroller “Atmega328” as Arduino Uno. Power factor correction using capacitor banks reduces reactive power consumption which will lead to minimization of losses and at the same time increases the electrical system‘s efficiency. Power saving issues and reactive power management has brought about the development of single phase capacitor banks for domestic applications. The development of this project is to enhance and upgrade the operation of single phase capacitor banks by developing a micro-processor based control system. The control unit will be able to control the individual capacitors in the capacitor bank and will operate in steps based on the variation in power factor. Current transformer and a Voltage transformer are used for sampling of the circuit current and voltage, so as to determine the power factor. The intelligent control using this micro-processor control system ensures even utilization of capacitor steps, minimizes number of switching operations and optimizes power factor correction.

Keywords: Power factor, Capacitor banks, Compensation, Microcontroller (Arduino uno).